Certain cell collection devices are known. In particular, a capsule sponge type cell collection device is described in PCT patent application number PCT/GB2006/003913. Such a device comprises an abrasive material capable of collecting cells from the surface of the oesophagus, together with means for its retrieval from the patient. Typically such devices are swallowable.
Known devices typically operate by swallowing the abrasive material in a compressed or stowed format. Upon reaching the stomach cavity, the material retaining the device in a compressed or stowed format is dissolved or weakened, permitting expansion of the compressed material back to its original size. Following this stage the device is then retrieved by physically pulling it from the subject's mouth. This pulling causes the device to travel out of the stomach cavity back up through the oesophagus and out through the patient's buccal cavity and mouth. In travelling along the subject's oesophagus, cells from the oesophageal lining are collected in the abrasive material part of the device. These cells are subsequently analysed to aid in the diagnosis or prognosis for the subject.
One known cell sampling device as described above is referred to as a capsule sponge. This device comprises a compressible sponge like material. This is typically attached to a cotton thread. The device is then compressed into a swallowable form, such as by incorporation into a gelatine capsule. Such known devices have typically had a cotton cord attached as the means of retrieval. This is a problem since cotton cords can shed fibres inside the subject. Moreover, cotton cord of thus type can be too rough. In addition, material may detach from the cord during use. Furthermore, the known device has suffered from the problem of loss inside the subject being sampled. This has typically occurred via separation of the uncompressed device from the cord for its retrieval. Furthermore, the known devices can be difficult to swallow due to friction of the cord on the oropharynx.
Thus, known cell sampling devices suffer from a range of problems and drawbacks. The present invention seeks to overcome problems associated with the prior art.